JP2008103898A - Encoding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an encoding technique which has good code efficiency and can easily achieve synchronization with encoded data. <P>SOLUTION: An encoding device 150 converts two-bit information data into four-bit encoded data according to a predetermined code rule. According to the code rule that the encoding device uses, one of four kinds of bit streams that the information data possibly include is converted into a four-bit bit stream wherein two bits at successive bit positions have values of "1" and a four-bit bit stream wherein all bits have values of "0" alternately. Other kinds of bit streams are converted into four-bit bit streams wherein only one bit has a value of "1" so that the bit streams having been encoded are different from one another. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an encoding device that encodes information data of a plurality of bits according to a predetermined encoding rule.

  Conventionally, various techniques have been proposed regarding a method of encoding data to be transmitted to a communication path. For example, Patent Documents 1 and 2 disclose an encoding method called a PPM (Pulse Position Modulation) method. In the PPM method, for example, 2-bit data indicating “00”, “01”, “10”, and “11” is changed to 4-bit data indicating “1000”, “0100”, “0010”, and “0001”, respectively. Converted.

  Patent Documents 3 and 4 disclose an encoding method called a CMI (Coded Mark Inversion) method. In the CMI method, 1-bit data indicating “1” is alternately converted into 2-bit data indicating “11” and “00”, and 1-bit data indicating “0” is converted into 2-bit data indicating “01”. Is done.

  Patent Document 3 also discloses a technique for transmitting a frame synchronization signal using a coding rule violation (CRV).

JP 2000-134186 A Japanese Patent Laid-Open No. 2000-267771 Japanese Patent Laid-Open No. 8-18611 JP 2002-94488 A

  In the above-described PPM system, code efficiency is good because a plurality of bits of data are encoded at a time. However, in the four types of bit strings indicated by the encoded data, the number of bits indicating “1” and the number of bits indicating “0” are the same, and therefore, from these bit strings, when synchronizing with the encoded data, There is a problem that a necessary reference phase cannot be detected and it is difficult to synchronize with encoded data.

  On the other hand, in the CMI method, the bit string indicated by the encoded data includes bit strings such as “11” and “00”, which are different from the bit string “01” in the number of bits “1” and “0”. The reference phase can be detected using these bit strings. Therefore, there is an advantage that when the encoded data is decoded, it is easy to synchronize with the encoded data. However, since 1-bit data is encoded, there is a problem that the code efficiency is not good.

  Accordingly, the present invention has been made in view of the above-described problems, and an object of the present invention is to provide an encoding technique that has good encoding efficiency and can easily synchronize with encoded data.

In order to solve the above problems, the invention of claim 1 includes means for converting N-bit (N ≧ 2) information data into M-bit (M ≧ 2 ^N −1) encoded data according to a predetermined coding rule. In the coding rule, with respect to 2 ^N types of bit sequences that can be taken by the information data, any one type of bit sequence has a value of L bits (2 ≦ L ≦ M) in which bit positions are continuous and “0” and An M-bit bit string indicating one of “1” and an M-bit bit string indicating the other of “0” and “1” are all alternately converted, and other types of bit strings are encoded. In order to make the subsequent bit strings different from each other, the value of only one bit or the K bits (2 ≦ K <L) in which bit positions are continuous is an M-bit bit string indicating one of “0” and “1”. An encoding device to be converted. N, M, and L are integers that satisfy the above conditions.

The invention according to claim 2 is the encoding apparatus according to claim 1, wherein in the encoding rule, M ≧ 2 ^N , and a value of a predetermined bit of the encoded data is “0”. And the information data is encoded so as to always indicate the other of “1”.

  The invention of claim 3 is the encoding apparatus according to any one of claims 1 and 2, wherein the information data is converted into an M-bit bit string in violation of the code rule. Is further provided.

  According to the first aspect of the present invention, the encoding efficiency is good because the information data of a plurality of bits are encoded at a time.

  Furthermore, when a certain type of bit string of information data is encoded, a bit string in which the same value continues with many bits can be obtained as compared with the case where other types of bit strings are encoded. The reference phase required when synchronizing with the encoded data can be detected. Therefore, when the encoded data is decoded, the encoded data can be easily synchronized.

  Further, even when N-bit information data is continuously encoded, the value of the binary code always changes in the encoded data, so that data errors when decoding the encoded data are reduced. can do.

  Further, regarding the encoded data, there is a pattern that cannot be generated by this encoding rule among the patterns that can be taken by the M-bit bit string. Therefore, error correction is performed when the encoded data is decoded using the pattern. be able to.

  According to the invention of claim 2, since the value of the predetermined bit of the encoded data does not change, when the encoded data is decoded, the predetermined bit is used to synchronize with the encoded data. In this case, it is possible to detect the reference phase required. Therefore, synchronization with the encoded data can be further simplified.

Furthermore, since M ≧ 2 ^N , among the patterns that can be taken by the M-bit bit string, patterns that are not generated by the coding rule of the present invention further increase, so that sufficient error correction is performed when decoding the encoded data. It can be carried out.

  According to the invention of claim 3, since there are many patterns that cannot be generated by the present coding rule among the patterns that can be taken by the M-bit bit string, the code rule violation data is generated by various methods. can do.

<One Embodiment of the Present Invention>
FIG. 1 is a diagram showing an encoding apparatus 150 according to an embodiment of the present invention. As shown in FIG. 1, encoding apparatus 150 according to the present embodiment converts 2-bit information data IFD into 4-bit encoded data CDD according to a predetermined encoding rule.

  FIG. 2 is a diagram illustrating a coding rule used in the coding device 150. As shown in FIG. 2, in this coding rule, the bit string “00” of the 2-bit information data IFD is converted into a 4-bit bit string “1000”, the bit string “01” is converted into a bit string “0100”, The bit string “10” is converted into the bit string “0010”. The bit string “11” of the information data IFD is alternately converted into the bit string “1100” and the bit string “0000”. Specifically, the encoding device 150 converts the input bit string “11” into the bit string “1100”, converts the next input bit string “11” into the bit string “0000”, and then inputs the bit string “0000”. The bit string “11” is converted into the bit string “1100”, and thereafter the same operation is performed.

  Information data IFD can be obtained by decoding the encoded data CDD encoded according to such a rule using the reverse rule. FIG. 3 is a diagram showing a decoding device 151 that decodes the encoded data CDD, and FIG. 4 is a diagram showing how the encoded data CDD is decoded in the decoding device 151. As shown in FIG. 4, in the decoding device 151, the bit string “1000” of the 4-bit encoded data CDD is converted into a 2-bit bit string “00”, and the bit string “0100” is converted into a bit string “01”. The bit string “0010” is converted into the bit string “10”. The bit string “1100” and the bit string “0000” of the encoded data CDD are both converted to the bit string “11”.

<Generalization of coding rules>
Next, more generally, the coding rule according to the present invention when coding the N-bit (N ≧ 2) information data IFD in the coding apparatus 150 will be described. In this coding rule, N-bit information data IFD is converted into M-bit (M ≧ 2 ^N −1) coded data CDD. In the above embodiment, the present coding rule when N = 2 and M = 4 has been described.

According to this coding rule, any one of the 2 ^N types of bit sequences that can be taken by the N-bit information data IFD has a value of “0” for each L bit (2 ≦ L ≦ M) in which bit positions are continuous. "M" bit string indicating one of "1" and "1" and an M bit bit string indicating the other of all "0" and "1" values. In the above embodiment, among the 4 (= 2 ² ) types of bit strings that can be taken by the 2-bit information data IFD, the bit string “11” is represented by 2 bits (in which the bit position is continuous at the first and second bits from the upper bit ( L = 2) is alternately converted to a 4-bit (M = 4) bit string “1100” in which each value is “1” and a 4-bit bit string “0000” in which all the bit values are “0”. ing.

Of the 2 ^N types of bit sequences that can be taken by the information data IFD, the other types of bit sequences have K bits (2 ≦ K) in which only one bit value or bit position is continuous so that the bit sequences after encoding are different from each other. <L) Each value of “L” indicates one of “0” and “1” (the same as the value indicated by each of the L bits in which the above bit positions are continuous among “0” and “1”). Each bit string is converted. In the above embodiment, among the four types of bit strings that can be taken by the 2-bit information data IFD, the bit strings “00”, “01”, “10” other than the bit string “11” Differently, the values are converted into 4-bit bit strings “1000”, “0100”, and “0010” in which the value of only 1 bit indicates “1”. N, M, and L are integers that satisfy the above conditions.

  5-10 show various embodiments of the present code rule. The embodiment shown in FIG. 5 differs from the embodiment shown in FIG. 2 only in that “11” of the information data IFD is converted to “1111” instead of “1100”. Compared with the embodiment shown in FIG. 2, the embodiment shown in FIG. 6 converts “11” of the information data IFD to “0010”, and alternately “10” into “1100” and “0000”. Only the point of conversion is different. In the embodiment shown in FIG. 7, “00” of the 2-bit information data IFD is converted into “1100”, “01” is converted into “0110”, “10” is converted into “0011”, and “11” is converted into “11”. It is alternately converted to “1110” and “0000”. In the embodiment shown in FIG. 8, 2-bit information data IFD is converted into 3-bit encoded data CDD. In this embodiment, “00” of the information data IFD is converted to “100”, “01” is converted to “010”, “10” is converted to “001”, and “11” is converted to “111” and “000”. It is converted alternately. The embodiment shown in FIG. 9 is obtained by replacing “1” and “0” in the encoded data CDD with respect to the embodiment shown in FIG. That is, in the embodiment shown in FIG. 9, “00” of the information data IFD is converted to “0111”, “01” is converted to “1011”, “10” is converted to “1101”, and “11” is converted to “11”. It is alternately converted into “0011” and “1111”. In the embodiment shown in FIG. 10, 3-bit information data IFD is converted into 8-bit encoded data CDD. In this embodiment, “000” of the information data IFD is set to “10000000”, “001” is set to “01000000”, “010” is set to “00100000”, “011” is set to “00010000”, and “100” is set to “100”. “0000”, “101” is converted to “00000100”, “110” is converted to “00000010”, and “111” is alternately converted to “11110000” and “00000000”.

<Effects of adopting this coding rule>
As described above, in the coding rule according to the present invention, N bits (N ≧ 2), that is, a plurality of bits of information data IFD are encoded at a time. Efficiency is good.

Further, according to this coding rule, any one of the 2 ^N types of bit sequences that can be taken by the N-bit information data IFD is represented by “0” and “1” for each of the L bit values having consecutive bit positions. Therefore, when any one type of bit string is encoded, a bit string in which the same value continues with more bits than when another type of bit string is encoded. Can be obtained. For example, in the example shown in FIG. 2, when the bit string “11” of the information data IFD is encoded, a bit string “1100” in which “1” is continuous in the upper 2 bits is obtained. The number of bits in which “1” continues is larger than the bit string in which only one bit is obtained by encoding the bit strings “00”, “01”, and “10”.

  As described above, according to the present coding rule, when a certain type of bit string of the information data IFD is encoded, a bit string in which the same value continues with more bits can be obtained than when other types of bit strings are encoded. Therefore, it is possible to detect a reference phase necessary when synchronizing with the encoded data CDD using the bit string. This will be described in detail below.

  For example, as an object to be compared with this coding rule, a coding rule that always converts “11” of the information data IFD to “0001” in the example shown in FIG. 2 is considered. This coding rule is called “4-value PPM”. In the encoded data CDD obtained by using this coding rule, only 1 bit indicates “1” and the number of bits indicating “1” is the same in all kinds of possible bit strings. Therefore, even when a signal indicating “1” is detected when decoding the encoded data CDD, the leading timing of the 4-bit encoded data CDD cannot be obtained using the signal, and the encoding is performed. It cannot be easily synchronized with the data CDD.

  For example, when decoding a bit string such as that shown in FIG. 11 encoded according to the comparison target coding rule, the rising timing T1 of the signal indicating “1” is used as the leading timing of the 4-bit encoded data CDD. When synchronized with the encoded data CDD, the encoded data CDD of “1000” is detected, and the information data IFD of “00” is obtained. On the other hand, if the falling timing T2 of the signal indicating “1” is the leading timing of the 4-bit encoded data CDD, the encoded data CDD of “0001” is detected, and the information data IFD of “11” is obtained. . As described above, in the coding rule to be compared, the information data IFD to be obtained changes depending on which timing is set as the head timing in the bit string to be decoded, so that a signal indicating “1” is simply detected. In this case, the reference phase cannot be detected, and synchronization with the encoded data CDD cannot be established. When decoding the encoded data CDD, since it is necessary to synchronize with the encoded data CDD, it becomes a problem that the encoded data CDD can be synchronized.

  In the present coding rule shown in FIG. 2, since the rising timing of the “11” signal is always the leading timing of the 4-bit encoded data CDD, the “11” signal is detected and the rising timing of the signal is determined. By synchronizing with the encoded data CDD as the reference phase, the information data IFD can be obtained. Therefore, when the encoded data CDD is decoded, it is possible to easily synchronize with the encoded data CDD.

  In the coding rule shown in FIG. 2, even if the information data IFD of “11” is converted to “0110” instead of “1100”, the reference phase is obtained by using the signal “11”. Can be detected. For example, if the transmission baud rate of the bit string to be decoded is F bits / second, a signal “11” is detected from the bit string to be decoded, and the timing (1 / F) seconds before the rising timing of the signal is 4 By using the start timing of the bit encoded data CDD, the information data IFD can be accurately restored.

  Further, according to the present coding rule, even when N-bit information data IFD is continuously encoded, the value of the binary code always changes in the encoded data CDD, so that the encoded data CDD is decoded. Can reduce data errors.

  For example, assuming that the information data IFD of “11” is always converted to “0000” in the coding rule shown in FIG. 2, when the information data IFD of “11” is continuously encoded, all bits are “0”. Is obtained. In such a bit string, since the value of the binary code is not changed, the head timing of the encoded data CDD cannot be detected, and it is difficult to accurately decode the encoded data CDD.

  On the other hand, in the coding rule of the present invention shown in FIG. 2, since the information data IFD of “11” is converted into “1100” and “0000”, the information data IFD of “11” is continuously encoded. Even in this case, the value of the binary code always changes in the bit string obtained by encoding. Therefore, the head timing of the encoded data CDD can be detected, and data errors when decoding the encoded data CDD can be reduced.

Furthermore, in the present coding rule, there is a pattern that cannot be generated in the present coding rule among the patterns that can be taken by the M-bit bit string with respect to the coded data CDD. Therefore, the coded data CDD is decoded using the pattern. Error correction can be performed. For example, in the coding rule shown in FIG. 2, “1000”, “0100”, “0010” among 16 (= 2 ⁴ ) types of patterns that can be taken by a 4-bit bit string with respect to 4-bit encoded data CDD. , “1100” and “0000” are used only. Therefore, error correction can be performed when the encoded data CDD is decoded using the remaining 11 types of patterns. An example is shown in FIG.

  As shown in FIG. 12, not only when the decoding target bit string is “1000” but also when “1001”, “1010”, and “1011” are converted to “00”. Further, not only when the bit string to be decoded is “0100”, but also when “0101”, “0110”, and “01111” are converted to “01”. Further, not only when the bit string to be decoded is “0010”, but also when it is “0001” and “0011”, each bit string is converted to “10”. Then, not only when the decoding target bit strings are “1100” and “0000”, but also when they are “1101”, “1110”, and “1111”, they are converted to “11”, respectively. Thus, in the example shown in FIG. 12, 1-bit or 2-bit error correction can be performed.

  2 and 6, the value of the predetermined bit of the encoded data CDD is the other of “0” and “1” (the above bit positions are continuous among “0” and “1”). It is preferable to encode the information data IFD so as to always indicate one that is different from the one indicated by each L bit value (the values of the least significant bits are fixed to “0” in FIGS. 2 and 6). . In this case, since the bit string of the encoded data CDD always includes bits whose value does not change, when the encoded data CDD is decoded, the encoded data CDD It is possible to detect a reference phase required for synchronization. Therefore, it is possible to more easily synchronize with the encoded data CDD. For example, in the example shown in FIG. 2, since the value of the least significant bit always indicates “0”, a “0” signal always exists in every 4 bits in the bit string to be decoded. . Therefore, the encoded data CDD can be accurately decoded by taking the reference phase at a timing such that a signal of “0” always exists every 4 bits.

Further, when the information data IFD is encoded so that the value of the predetermined bit of the encoded data CDD always indicates the other of “0” and “1”, M ≧ 2 ^N , so that the M-bit bit string is Of the possible patterns, patterns that are not generated by this coding rule further increase. For example, in the coding rule shown in FIGS. 2 and 6, since the number of bits of the encoded data CDD is set larger than the coding rule shown in FIG. 8, the coding rule of FIGS. There are more patterns that are not generated than the coding rule of. Therefore, sufficient error correction can be performed when the encoded data CDD is decoded.

<CRV (Coding Rule Violation)>
In the optical transmission apparatus described in Patent Document 3 described above, the CMI method is used as an information data encoding method. In the CMI method, “1” information data is alternately converted into “11” and “00”, and “0” information data is converted into “01”. As a method of generating data in violation of such a coding rule, there are a method called CRV0 and a method called CRV1. In CRV0, data that violates the coding rule is generated by converting the information data of “0” to “10” instead of “01”. In CRV1, the information data of “1” is changed to “11”. Instead of alternately converting “00”, data that violates the coding rule is generated by continuously converting to either one of the bit strings.

  As described above, according to the CMI coding rule, information data is converted into 2-bit coded data, and thus a method for generating coding rule violation data is limited to some extent.

In the coding rule according to the present invention, the information data IFD is converted into M-bit coded data CDD, and M ≧ 2 ^N −1 and N ≧ 2, so that the information data IFD is a code of 3 bits or more. Is converted into digitized data CDD. With respect to the encoded data CDD, there are many bit string patterns that are not generated by this encoding rule. Therefore, compared to the case where data violating the CMI coding rule is generated, the coding rule violating data can be generated by more methods. Hereinafter, a method for generating coding rule violation data will be described in detail by taking the coding rule shown in FIG. 2 as an example.

  For example, in the encoding device 150 described above, coding rule violation data can be generated by converting the information data IFD of “00”, which is originally converted to “1000”, to “1001”, for example. The decoding device 151 converts not only the encoded data CDD of “1000” but also the encoded data CDD of “1001” into the information data IFD of “00”. Thereby, “00” information data IFD having a special meaning such as a frame synchronization signal can be distinguished from other “00” information data IFD and input to the decoding device 151.

  As another example, coding rule violation data can be generated by converting information data IFD of “01”, which is originally converted to “0100”, to “0101”, for example.

  As another example, code rule violation data can be generated by converting “10” information data IFD, which is originally converted to “0010”, into “0011”, for example.

  As another example, coding rule violation data can be generated by converting “11” information data IFD, which is originally converted to “1100”, to “1101”, for example.

  As another example, code rule violation data can be generated by converting “11” information data IFD, which is originally converted to “0000”, to “0001”, for example.

  As another example, the information data IFD of “11”, which is originally converted alternately to “1100” and “0000”, is continuously converted to “1100” or continuously to “0000”. Thus, coding rule violation data can be generated.

<Application example of the present invention>
Next, a system example using the encoding device 150 and the decoding device 151 according to the present invention will be described. Below, the case where the encoding apparatus 150 and the decoding apparatus 151 which concern on this invention are used for the electronic shelf label system (ESL system / Electronic Shelf Label System) introduced in a supermarket, a convenience store, etc. is demonstrated.

  FIG. 13 is a diagram illustrating a state in which the electronic shelf labels included in the electronic shelf label system according to the present embodiment are arranged on the product shelf of the store. In the electronic shelf label system, portable electronic shelf labels that display product information such as selling prices are arranged corresponding to each product. Then, a communication signal including a selling price based on the product master is transmitted to each electronic shelf label from the distribution side device that distributes information, and the selling price is displayed on each electronic shelf label. Thus, the correct selling price that matches the selling price at the time of settlement is displayed on the electronic shelf label, and the correct selling price is transmitted to the customer.

  As shown in FIG. 13, the product shelf 60 is divided into a space called a face 61, and the same type of products 6 are collected and placed on each face 61. The electronic shelf label 5 is attached to the frame 62 of the product shelf 60 at a position corresponding to each face 61. That is, each electronic shelf label 5 is associated with one product 6 (more precisely, one product type), and a frame 62 in the vicinity of the corresponding product 6 (generally, the lower side of the product 6). Placed in. Each electronic shelf label 5 is provided with a display, on which the selling price of the corresponding product 6 is displayed. The customer (consumer) of the store recognizes the selling price of the product 6 by such display of the electronic shelf label 5.

  The electronic shelf label 5 is a portable device, and can be removed from the frame 62 and rearranged at another position so as to cope with the change in the arrangement of the product 6. In the present embodiment, a plurality of product shelves 60 as shown in FIG. 13 are arranged in the sales space in the store.

  FIG. 14 is a diagram illustrating a configuration example of the store information system 100 including the electronic shelf label system 1 applied to a store. As shown in FIG. 14, the store information system 100 includes a store controller 2 and a POS system 3 along with the electronic shelf label system 1. The POS server 31 included in the POS system 3 and the ESL server 10 included in the electronic shelf label system 1 are connected to the store controller 2 via the LAN 21. Thereby, data communication is enabled among the store controller 2, the POS system 3, and the electronic shelf label system 1.

  The store controller 2 is composed of a general computer and functions as a device that manages the store information system 100 in an integrated manner. In addition, the store controller 2 is connected to an external network such as the Internet, and can communicate with a computer such as a server device disposed in a headquarter center that manages the store in an integrated manner via the external network.

  The POS system 3 is a system that collects and analyzes information related to the sale of products at the time of sale, and includes a plurality of registers 32 that perform product settlement together with a POS server 31 that collectively manages the POS system 3. ing. The POS server 31 and the register 32 are connected by a dedicated communication cable.

  The POS server 31 is composed of a general computer, and the hard disk stores a product master 301 indicating various information related to products such as selling prices. In each of the plurality of registers 32, the product is settled based on the selling price described in the product master 301.

  Information related to all products in the store is centrally managed by the product master 301. Information described in the product master 301 includes “product code” that is product identification information, “product name” that is the name of the product, “normal price” that is the normal selling price, and “sale price that is the selling price in the sale. ”,“ Special sale period ”, which is a period for carrying out special sale.

  The electronic shelf label system 1 is broadly divided into a plurality of electronic shelf labels 5 described above and a distribution-side device 40 that distributes “sale prices” of products to be displayed on the electronic shelf labels 5.

  The distribution side device 40 includes an ESL server 10 that is a server device that manages the electronic shelf label system 1 in an integrated manner, and a plurality of communication devices 4. The ESL server 10 and the plurality of communication devices 4 are connected to each other via a dedicated communication cable 22 so that data communication is possible between them. Each communication device 4 performs infrared communication with the electronic shelf label 5. The communication device 4 is arranged at a substantially constant distance on the ceiling of the sales space so that it can communicate with all the electronic shelf labels 5 arranged in the sales space.

  The configuration of the ESL server 10 as hardware is the same as that of a general computer. FIG. 15 is a diagram showing a configuration of the ESL server 10. The ESL server 10 includes a CPU 11 that performs various arithmetic processes, a ROM 12 that stores basic programs, a RAM 13 that serves as a work area for the arithmetic processes, a hard disk 14 that stores programs and various data files, a display 15 that performs various displays, a keyboard, An input unit 16 composed of a mouse or the like, a data communication unit 17 having a data communication function via the LAN 21, and an interface 18 for communicating with the communication device 4 are provided. A signal indicating “sale price” to be transmitted to the electronic shelf label 5 is transmitted to the communication device 4 via the interface 18.

  A dedicated program is stored in advance in the hard disk 14 of the ESL server 10, and various functions as the ESL server 10 are realized by the CPU 11 performing arithmetic processing according to the program. The hard disk 14 of the ESL server 10 stores a product file 101 that is a data file indicating various information (product data) related to the product.

  FIG. 16 is a diagram illustrating an example of the product file 101. As shown in FIG. 16, the product file 101 has a table format, and each record 102 indicates information related to one product. Specifically, “product code”, “product name”, “normal price”, “sale price”, “sale period”, and the like are registered for each record 102. These pieces of information are the same information as the product master 301 stored in the POS system 3 described above, and are registered based on the information in the product master 301 through communication between the ESL server 10 and the POS system 3. For this reason, the information in the product file 101 and the information in the product master 301 are the same.

  Further, in each record 102 of the product file 101, one “device code” that is a hardware ID unique to each of the plurality of electronic shelf labels 5 provided in the electronic shelf label system 1 is registered. Thereby, the product and the electronic shelf label 5 are associated with each other in a one-to-one relationship (linked). By using this “device code”, the “selling price” of a certain product is transmitted to the electronic shelf label 5 corresponding to the product.

  Next, the communication device 4 will be described in detail. FIG. 17 is a diagram illustrating a configuration of the communication device 4. As shown in FIG. 17, each communication device 4 includes the above-described encoding device 150 and decoding device 151, a drive unit 41, an infrared light emitting element 42 configured by LEDs, and an infrared configuration configured by photodiodes. A light receiving element 43 and a data reproducing unit 44 are provided.

  The encoding device 150 encodes data indicating the “selling price” given from the ESL server 10 according to the above-described encoding rule, and outputs the encoded data to the drive unit 41. The drive unit 41 drives the infrared light emitting element 42 based on the input encoded data. As a result, the infrared light emitting element 42 outputs an infrared signal IR1 modulated with the encoded data from the encoding device 150.

  FIG. 18 is a diagram showing the relationship between the encoded data output from the encoding device 150 and the infrared signal IR1. As shown in FIG. 18, in the infrared light emitting element 42, the encoded data CDD blinks at a predetermined frequency while the binary code of “1” indicates “1”, and turns off while it indicates “0”. In the example shown in FIG. 18, the infrared light emitting element 42 is turned on four times while 1-bit data indicates “1” in the encoded data CDD. Accordingly, when the data of 2 bits continuously indicates “1” in the encoded data CDD, the infrared light emitting element 42 is lit 8 times.

  The infrared light receiving element 43 receives the infrared signal IR2 output from the electronic shelf label 5, converts the infrared signal IR2 into an electrical signal ES, and outputs the electrical signal ES to the data reproducing unit 44. The data reproducing unit 44 amplifies the input electric signal ES, reproduces the encoded data generated by the electronic shelf label 5 based on the amplified electric signal ES, and outputs the encoded data to the decoding device 151. The decoding device 151 decodes the input encoded data and outputs it to the ESL server 10. As will be described later, the electronic shelf label 5 also generates encoded data using the encoding rule according to the present invention.

  FIG. 19 is a diagram showing the relationship among the infrared signal IR2, the electrical signal ES, and the encoded data reproduced by the data reproducing unit 44. As shown in FIG. 19, the infrared light receiving element 43 outputs an electrical signal ES having the same waveform as the infrared signal IR2 from the electronic shelf label 5, and the data reproducing unit 44 receives the electrical signal ES from the electronic shelf label 5. The generated encoded data is reproduced.

  Next, the electronic shelf label 5 will be described in detail. FIG. 20 is a diagram showing the configuration of the electronic shelf label 5. As shown in FIG. 20, on the front surface of the electronic shelf label 5, a display 51 for displaying the “selling price” of the product and a communication unit 54 responsible for communication with the distribution side device 40 are arranged. The display 51 is composed of, for example, a dot matrix type liquid crystal display.

  The communication unit 54 includes an infrared light emitting element 52 that transmits the infrared signal IR2, and an infrared light receiving element 53 that receives the infrared signal IR1 from the communication device 4. The infrared light emitting element 52 is composed of, for example, an LED. The infrared light receiving element 53 is constituted by a photodiode, for example, and converts the infrared signal IR1 into an electric signal.

  Below the display 51, an overlay label 55 on which a barcode indicating “product name” and “product code” related to the product with which the electronic shelf label 5 is associated is printed. If the electronic shelf label 5 is not attached with labels, it is difficult to grasp which product the electronic shelf label 5 is associated with. Visually matched.

  In addition, the electronic shelf label 5 includes therein a small battery 56 that supplies driving power, and a control unit 57 that includes an integrated circuit that controls the operation of the apparatus. Although not shown, the control unit 57 includes the encoding device 150 and the decoding device 151 described above, and further includes a drive unit and a data reproduction unit similar to those of the communication device 4. The control unit 57 amplifies the electric signal output from the infrared light receiving element 53 in the data reproduction unit, reproduces the encoded data generated by the communication device 4 from the amplified electric signal, and converts the encoded data into the encoded data. Decryption is performed by the decryption device 151 to obtain data indicating “selling price”. In addition, when receiving data indicating “sale price”, the control unit 57 generates data indicating that and encodes the data by the encoding device 150. Then, using the drive unit, the control unit 57 drives the infrared light emitting element 52 based on the encoded data generated by the encoding device 150, and outputs the infrared signal IR2 from the infrared light emitting element 52. In addition, the control unit 57 includes a memory 58 that stores various types of information. The memory 58 stores data indicating “selling price” obtained from the infrared signal IR1, and data indicating the device code of the own device. The control unit 57 reads data indicating “sale price” from the memory 58 and controls the display 51 based on the data. As a result, “selling price” is displayed on the display 51.

  Next, a series of operations of the electronic shelf label system 1 until the selling price is displayed on the electronic shelf label 5 will be described. In the electronic shelf label system 1 of the present embodiment, the distribution of the “sale price” from the distribution side device 40 to the electronic shelf label 5 is performed when the system is activated and when the “sale price” displayed on the electronic shelf label 5 is updated. And so on. Here, when the “sale price” is updated, the normal price of the merchandise master 301 is changed, or when the sale price is changed from the normal price to the special sale price when the special sale is performed. When the system is activated, the “selling price” is distributed for all products in the store. On the other hand, when the “sale price” is updated, the “sell price” is distributed only for the target product. As a result, the “sale price” displayed on the electronic shelf label 5 and the “sale price” at the time of settlement by the register 32 are always matched. In the following, the operation related to the distribution of “sale price” for one product will be described. In the following description, the target product is referred to as “target product”.

  First, in the ESL server 10 of the distribution side device 40, the record 102 related to the target product in the product file 101 is referred to, and the “sale price” to be distributed among the “normal price” and the “sale price”, and “ "Device code" is acquired. The acquired “device code” is the “device code” of the electronic shelf label 5 corresponding to the target product, and the acquired “sell price” is the “sell price” that the electronic shelf label 5 should display. Become. These “selling price” and “device code” are transmitted as electrical signals to the communication device 4 via the communication cable 22.

  The signals indicating the “selling price” and “device code” are encoded in the communication device 4. The communication device 4 controls the infrared light emitting element 52 based on the obtained encoded data. As a result, the infrared signal IR1 including the information of “selling price” and “device code” is output from the communication device 4.

  The infrared signal IR1 output from the communication device 4 is received by the communication unit 54 of the electronic shelf label 5 and converted into an electrical signal. The control unit 57 reproduces the encoded data generated by the communication device 4 from the electrical signal obtained by the communication unit 54, decodes the encoded data, and indicates the “sales price” and “device code”. To get.

  Next, the control unit 57 determines whether or not the obtained “device code” matches the device code of the own device stored in the memory 58 in advance. At this time, if the “device code” does not match that of the own device, the received infrared signal IR1 is determined to be a signal for another electronic shelf label 5, and the processing is terminated as it is.

  On the other hand, if the “device code” matches that of the device itself, the received infrared signal IR1 is determined as a signal for the device itself, and the display on the display 51 is updated by the control unit 57 according to the obtained “selling price”. Is done.

  With the operation as described above, the “selling price” is distributed from the distribution side device 40 to the electronic shelf label 5.

  After the display on the display 51 is updated, an infrared signal IR2 including information indicating that data indicating “sale price” has been normally received is output from the infrared light emitting element 52 of the electronic shelf label 5. The infrared signal IR2 is received by the communication device 4, and information included in the infrared signal IR2 is transmitted to the ESL server 10. Thereby, the ESL server 10 of the delivery side apparatus 40 can confirm whether or not the data indicating the “selling price” has been normally received by the electronic shelf label 5. Therefore, for example, when the infrared signal IR2 is not output from the electronic shelf label 5, it is determined that the data indicating “selling price” has not been normally received by the electronic shelf label 5, and the ESL server 10 returns the infrared signal IR2 as a response. Until this is done, it is possible to repeatedly output data indicating “sale price”. Thereby, the display of the electronic shelf label 5 can be reliably updated, and the reliability of the system can be greatly improved.

  In this way, in the information communication between the distribution side device 40 and the electronic shelf label 5, the data between the distribution side device 40 and the electronic shelf label 5 is obtained by using the encoding method according to the present invention. The transmission rate can be greatly improved. In particular, when the dot matrix type display is adopted as the display 51 of the electronic shelf label 5, the display data is greatly increased as compared with the case where the segment type display is adopted. It is very effective to use the encoding method according to the present invention for information communication with the tag 5.

  In the above example, the case where the encoding method according to the present invention is applied to the electronic shelf label system has been described, but it goes without saying that it can be applied to other systems.

It is a figure which shows the encoding apparatus which concerns on embodiment of this invention. It is a figure which shows the code rule which concerns on embodiment of this invention. It is a figure which shows the decoding apparatus which concerns on embodiment of this invention. It is a figure which shows a mode that encoded data is decoded in the decoding apparatus which concerns on embodiment of this invention. It is a figure which shows the code rule which concerns on other embodiment of this invention. It is a figure which shows the code rule which concerns on other embodiment of this invention. It is a figure which shows the code rule which concerns on other embodiment of this invention. It is a figure which shows the code rule which concerns on other embodiment of this invention. It is a figure which shows the code rule which concerns on other embodiment of this invention. It is a figure which shows the code rule which concerns on other embodiment of this invention. It is a figure which shows the data encoded with the conventional code rule. It is a figure which shows a mode that error correction is performed with respect to the data encoded with the code rule which concerns on embodiment of this invention. It is a figure which shows a mode that the electronic shelf label with which the electronic shelf label system using the code | symbol rule which concerns on this invention is provided is arrange | positioned. It is a figure which shows the structural example of the store information system containing the electronic shelf label system in which the code rule which concerns on this invention is used. It is a figure which shows the structure of an ESL server. It is a figure which shows the example of a goods file. It is a figure which shows the structure of a communication apparatus. It is a figure which shows the relationship between encoding data and an infrared signal. It is a figure which shows the relationship between an infrared signal, an electrical signal, and encoding data. It is a figure which shows the structure of an electronic shelf label.

Explanation of symbols

1 Encoder IFD information data CCD encoded data

Claims (3)

Means for converting information data of N bits (N ≧ 2) into encoded data of M bits (M ≧ 2 ^N −1) according to a predetermined coding rule,
In the code rule,
Regarding 2 ^N types of bit strings that can be taken by the information data,
Any one type of bit string includes an M-bit bit string in which each value of L bits (2 ≦ L ≦ M) in which bit positions are continuous indicates “0” or “1”, and all bit values are “0”. Are alternately converted to an M-bit bit string indicating the other of "1" and "1",
In other types of bit strings, values of only one bit or K bits (2 ≦ K <L) having consecutive bit positions are “0” and “1” so that the bit strings after encoding are different from each other. An encoding device that converts the data into an M-bit bit string indicating the one of the above. The encoding device according to claim 1, comprising:
In the code rule,
M ≧ 2 ^N and
An encoding apparatus, wherein the information data is encoded such that a value of a predetermined bit of the encoded data always indicates the other of “0” and “1”. An encoding device according to any one of claims 1 and 2, comprising:
An encoding apparatus, further comprising means for converting the information data into an M-bit bit string in violation of the encoding rule.

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